Molding apparatus



Jan. 4, 1949.

F. J. M DONALD MOLDING APPARATUS 2 Sheets-Sheet 1 Filed Aug. 18, 1945 3JUL/577. 25."

- E5272 J'ZW JUH ZE W /W W Jan. 4, 1949.

F. J. M cDoNALD 2,458,182

MOLDING APPARATUS 2 Sheets-Sheet 2 Filed Aug. 18, 1945 Patented Jan. 4,1949 UNITED STATES OFFICE 15 Claims.

This invention relates to the molding of articles from plastic materialsand relates particularly to apparatus for moldingdeeply contoured hollowarticles such as helmet liners, binocular carrying cases and the'like,from thermosetting materials.

It is an object of this invention to provide improved apparatus formolding articles from blanks comprising thermosettin-g or thermocuringmolding materials whereby the blank is quickly and efficientlytransformed into a finished molded article of superior properties with areduction in the cost of' labor and materials and with an increaseofefiiciency. Another ob ject is to provide apparatus which-is quickly andeasily adaptable to the molding of a variety of molding materialsrequiring a wide difference in molding temperatures'and pressures. It isa further object of this invention to provide apparatus for moldingwhich is light and more easily operated by labor of the-light weightclass and which, by virtue of its lightness, shall be less expensive tobuild and install.

Further objects will become apparent in the detailed description of theinvention which is to follow.

The molding apparatus of this invention broadly comprises a take-apartmold comprising male and femalemembers, one of the mold members beingmovably mounted for movement into and out of molding engagement with theother. Also, one of the mold-members is provided with a flexibledistensible diaphragm associated therewith for defining aninternalpressure chamber by means of whichthe "m'o'lda'ble material is forcedagainst the internal shape-determining surfaces of the other moldmember. In conjunction with the take-apart mold there is provided acompound pressure-exerting means comprising a low pressure; fast-actionair cylinder for bringing the -movable"iriold member iii-to alignmentand. approximate molding relation to the other mold member, means tolock 'theair piston in such position and a short-travel high pressurehydraulic cylinder acting from the air piston to bring the mold memberstightly together in final molding 'relatibnship.

This invention is an improvement upon the subject matter of my copendingapplication Serial No. 502,59'7 filed September 1'6, i943, now PatentNo. 2,415,504, issued February 11, 1947.

The invention will be describedin grater'da tail with reference to anillustrative embodiment trative embodiment of this invention, having atake-apart mold suitable for molding binocular carrying cases and thelike;

Fig. 2 is a horizontal section taken along the line 22 of Fig. 1;

Fig. 3 is a vertical section taken along the line 33 of Fig. 1;

Fig. 4 is an enlarged side elevation of partof the apparatus of Fig. l,disclosing details of the mold members and the locking mechanism;

Fig. '5 is a horizontal section taken along the line 5 -5 of Fig; 4;

Fig. 6 is a horizontal section taken along the line 6 6 of Fig 1;

Fig. 7 is a perspective view of a binocular carrying case member. orsimilar article molded in the apparatus of Fig. land partially brokenaway to disclose the character of the fabric reinforced thermosettinplastic-material. I

Referring to the drawings; the moldingapparatus of this inventioncomprises a frame con-' sisting of two upstanding columns ill, in ofchannel iron and a top cross-member ll composed of channel iron andsteel plate. The columns iii, it may be fastened to the floor, or othersupporting structure, by means of angle irons I2, !2. A male mold memberindicated generally by the numeral I3 is suspended between the columnsIll, Ill at the top thereof and hanging downwardly therefrom. A femalemold member, indicated generally by the numeral 14, is mounted upon thefloating piston l5 of a short-stroke, heavy-walled hydraulic cylinderit. The piston i5 is provided with a heavy rubber sealing gasket 150.which is secured to the face of the piston as shown in Fig. -1. Fluidunder pressure is supplied to cylinder it through pipe H, a flexiblecommunicating hose lS being used to connect the fluid inlet pipe ll tothe fluid supply line 59. Two-way valve 20 serves to connect pipe ii tothe fluid supply line 19 or to the exhaust line ii.

The hydraulic cylinder 16 rests upon a cylinder supporting plate 22which in turn is engaged by the piston rod 23 of a light-walled aircylinder 24. Cylinder 26 is supported from the columns lil, H! bychannel beams 24a, 25a. Low pressure air is supplied respectively to thebottom or top of the air cylinder 24 through pipes 25, E541 and four-wayvalve 26. A locking mechanism adapted for manual operation consists ofopposed locking seats comprising plates 21, 2?, secured to the columnsIll, 10 and a latch casting 23 on the air piston '23 just below thesupporting plate 22 and adapted to ee-rotated into and out of engagementwith-thelocking seats '21, 21 by manual rotation of the casting 28 bymeans of the handle 28a. The locking mechanism forms a, bridge betweenthe columns l0, thereby positioning the air piston 23 in an approximatemolding position with the mold members slightly separated.

The male mold member l3 comprises an upper plate 29 integral with a longthin core portion 30 which is cored out for steam heating. A metalbag-retainin ring 3! in conjunction with the upper plate 23 of the malemold member, holds the flared skirt of a distenslble diaphragm or bag 32in place surrounding and overlying the metal core portion 30 and forminga fluid-tight pressure chamber therewith. The male mold member I3 ismounted between the upright columns [0, l0 and is supported by extendinglugs 33, 33 which rest freely on angle irons or blocks 34, 34 which arebolted to the columns l0, ID. The male mold member I3 is laterallypositioned on the supporting blocks 34, 34 by pins 35, 35 extendingupwardly from the blocks 34, 34. Steam for heating the mold member I3 isintroduced to the core portion 30 through pipes 36, 33a. Fluid underpressure, preferably an evaporable fluid like water, is introduced tothe chamber between the bag and the core portion 30 through pipes 31,37a. The pipe 31a contains a needle valve 38 for retardin the flow offluid to the bag 32, Fluid is exhausted from the chamber through pipe3'! by closing the cut-off valve 39 and opening valve 40 so as to allowexhaust through the check valve 4|.

The female mold member I4 may be a hollowed out concave metallic modmember of the takeapart type adapted to be opened for removal of themolded article. The female mold I4 is split horizontally along a flatsurface at the bottom of the mold so as to form a fiat bottom platen 42and an upper portion. The upper portion in turn is split vertical y toform a hinged side portion 43 and a fixed side portion 44. The fixedside portion 44 is fastened in place on the bottom platen 42 bycountersunk stud bolts 45, 45 passing entirely through the bottom platen42. The hinged side portion 43 is arranged to be manually opened bygrasping lever 46 and swinging the side portion 43 outwardly anddownwardly on hinges consisting of bolts 41, 41 fixed in the corners ofmold section 43 and passed through slotted ho es 48, 48v in bottomplaten 42. The two side portions of the female mold I4 are provided witha guide device 49 which aligns the two side portions while the mold isbeing closed. All three portions of the female mold member M are coredfor heating, steam or the like being supplied to the bottom platen 42through pipes 50, 50; to the hinged side portion 43 through the pipes5|, 5|; and to the fixed side portion 44 through pipes 52, 52. To permitthe necessary vertical movement of the entire female mod I4, theaforementioned steam pipes need to be connected to the steam supply bymeans of flexible communicating hose (not shown).

When a split female mold member is used in conjunction with an internalpressure exerting means such as the extensible bag, it is desirable toexert pressure at right angles to the vertical split in the mold toclose the mold upon the blank of moldable material. In the illustrativeembodiment, a second short-travel high pressure hydraulic cylinderhaving a piston El acts horizontally upon the female mo d member, thepiston 6| having projecting faces Gla, 61a making contact with similarprojecting faces 4 a, 4% on the fixed section 44 of the female mold. Thepiston BI is fitted with a heavy rubber sealing gasket Blb. The cylinder60 is supported from the columns l0, ID by means of clamp bars 62,62,which are bolted to the columns Hi, It by bolts 62a, 62a. The cylinder60 is secured to the bars 62, 62 by four nuts 60a, 64a. The bars6262also serve as guides for the female moldmember l4 while it is beingraised to the upper position. When the piston 61 is urged to the left(Figs. 1

and 2), the projecting faces 61a, em on the piston make contact with theprojecting faces 44a, 44a of the mold member 44. Since the two femalemold members 43, Marc mounted on platen 42 which is supported byfloating piston l5 in cylinder l6, and cylinder I6 is in turn mounted onpiston 23, there is necessarily a slight amount of lateral play in thiswhole assembly when piston 23 is extended as shown in Fig. 1. Inasmuchas the clearance between the hooked ends of clamp bars 62, 62 and moldsection 43 is only a few thousandths of an inch, the Whole mold assemblyl4 and its supporting piston ismoved slightly to the left and the twomold sections 43, 44 are squeezed together between piston 8i and thehooks of clamp bars 62, 62 as piston 6! is urged further to the left,the coiled springs 63, 63 serving to retiun the piston 6| to the openposition when the pressure in cylinder 64 is released. Fluid underpressure may be supplied to cylinder 6 through pipe I9 by opening valve20'. Fluid may be exhausted from cylinder 683 by turning valve 20 to theexhaust position whereby fluid is exhausted through line 64.

To facilitate the opening of the mold and to break the parts of thefemale mold away from the mo ded article, an auxiliary kicker cylinder10 is located opposite the lower rest position of the air piston 23. Thecylinder 10 is supported from the columns l0, It) by brackets H, H. Thecylinder 10, as shown in Fig. 1, is provided with projecting studs 12a,12a which pass through piston 12 and on which the p'istonis slidablymounted. A heavy rubber sealing gasket 73 is provided for piston 12 andcoiled springs l4, 14 are mounted in compression between the heads ofstuds 12a, 72a and the face of piston 12 to return piston 12 to itsretracted position when the pressure in cylinder 10 is released. Aspiston 12 is urged to the left (Fig. 4) its face engages kicker bars 15,15 which are recessed in the floating piston l5 of the verticalhydrauliccylinder Hi. The kicker bars 15, 75 engage the bottom corners of thehinged side portion 43 and move the side portion of the mo d outslightly until the bolts 41, 47 are at the outer end of the slottedholes 48, 48 thereby'permitting the side portion 43 to swing outwardlyand downwardly as shown in the broken lines of Fig. 4. The cylindershould be a fast-action cylinder, but low pressure air in theneighborhood of 100 pounds per square inch may be used to actuate thepiston. Air is supplied to cylinder 1 from supply line 16 throughflexible coupling 11 and two-way valve 18. Air is exhausted fromcylinder 10 through line 19.

For supporting the air piston and the female mold in the loyver or openposition, a rest support is provided consisting of bars 80, extendingacross the channel beams 24a, 24a and ad- J'ustable bolts or pins 8|, 8|extending upwardly gl'zierefrom to engage the cylinder supporting plateIn operation of the apparatus described above, a blank of plasticmoldable materiaLwhich may comprise fabric layers treated with asuitable thermosetting resin, is inserted; inthezopened femalemold-memberrwhilesit is :at thei lower: rest-1 postion and the. mold-isrraised to: the upperirestt position by turning zifourrwayz valve.abuse-as to; connect pipe..25:ito the airvsupplyrline 16;-- ,Whem

the piston 23 has reached a positionoppositethe locking seatsll, 21,therotarylatchcastingfiBf-is rotated by hand-into engagement withthelock-s ingseats 21, 21. High pressure fluidiis: tl:1,en;ad-.v

phragm; 32; by closing: valve 4 ll and :turningwalvese;

Hand-39 to the open position; Since the-volume ofthe bag '32 issubstantially lesssthanthati of,

the cylinders l B-and EiL'the -needle.:valve 38;'is:in= terposed in theline'to reducethe raterof:flowtherein. It-musta be notednthat thecored-.rpore tionsof: the mold are continuously heated by" steam; forthe cycle of molding; operations nor.-

mallyis 'too short 'to permitheatingand cooling ofthe mold parts. Afterthemold has-been com pletely closedby the coaction. of the two-hydrauliccylinders, the bag continues to'fill andthe cure" begins. The ,thin.layerz'of' water or: other vaporizablezfluid. contained between-the; bagand the male-mold member :is quickly heated to a -tem perature'nearlythat of the malemold' and. heat is transmitted from the waterthrough the diaphragm to'theinsideof the blank ofmoldable material; Inthe above inflation steps it isnecessary-to i thickness 'of the moldedarticle and the temperatures'ofthemold'parts; When the art cle'has"set'the procedure foropening the mold is the reverse of closing: Again adifferential in the rate of'flow ally-sixto" eight minutes dependingupon the' is'utilized to deflate the diaphragm and the-cyl inders. inproper'sequence, the bag being deflated first'soas'to free the diaphragmfrom the molded article. The-bag. is deflated first-by: closing valve39-and opening valve 48*, the check valve Mpermitting the fluid to'flash off as steam, while'preventing influx of vapor air to such anextent that upon condensation of'the vapor in line'3l; a'vacuum'isproduced therein and the diaphragm-32 is'pulled away frommolded articleand collapsed upon'the male mold member [32' Cylinders-Iii" andfiil areexhausted by turning valve 20 to the exhaust'position. The release ofpressurein the diaphragm132 and in the cylinders iiiland l6completely'frees the male mold member 13 from the The air piston23'maythen be lowered by rotating the rotary latch ZKand turn-- moldedarticle.

ing' the four-way valve-25 so: as to 'connectthe airsupnly lineltrthrough pipe-25a to the topof the cylinder 2 4;

The female mold member is opened-by turning" valve 18 so as'to admit airto cylinder ltlthereby I causing piston Tito engage kickerbars'It'fwhich push'the hing d side portion of the female'mold" membersidewise in the slotted holesof the-hinges thereby permitting. thelowering of the hinged drawings.

The pressure exerted by the hydraulic cylin V 6.. surezzhaszbeen fOUIICIitQJbe'} imtheyneighborhood-i of=:.500 :to: :1 0,0.0 poun dsspierisquarezdnchr if or most thermosettingetype resins;v Steam Hat 500 to,iOGOEpoun-ds zperrsquarerinchzzi-s much-.tooi'hotifom :5 curing ofplastics for the temperatures:required;

for. curing these?-. resi-ns this. onlyabout. 350 Fahrenheit-l Steam";at-i 350?- is much tool low in: pressure for: compressingrthe moldingmaterial.- so: themuse of. steam as avsinglesheating-andpres? sur.e.-exerting; medium; is .not feasible. It-is seen... therefore thatthew-compound pressureeexerting system .of,-:this.- invention L in;combination-i with... steam. ot:-;t11e. -propertemperature comprisesua.flexible means in which the conditions of tem-.' perature and pressure,may; be varied. independe ently ,1 of. each ,other... Further; sincethe. high. pressure. :hydraulic-cylinders....are...short, a great.economy inlthetusesof ,high pressure fluid is. real.- ized and. thesize. ofrtheshydraulicrpressure pumps is reduced v Tdsimplify pipingarrangements and. to eliminate, the. necessity, of .a number of highpressure; fluidpumps, it is preferred to use thesamepressure in the twohydraulic cylindersasin the. bag The two-hydraulic'cylinders desirablyshould be designed to .have areas'larger than therespec= tive projectedareas of the" bag" on the pistons. Inthis way the force tending to"close the" mold exerted by the cylinders; exceeds the' iorce exerted bythe bag which" tends" to'open the mold;- However; should the conditionswarrant it; ahi'gher pressure could be used 'in-the cylinders" or* viceversa. With suitable pressure reducing valves'adjustableto thedesired=-pressures= it" is possible 'to obtain" great flexibility ofmolding conditions:- therebyma-king possible the molding of a varietyofmoldable materials;

The distensiblediaphragm or internal. pressure bag may-be madeef anysuitable extensible rubber or other rubber like material such as eithera-natural" or synthetic: rubber preferably compounded for: resistance toheat; It-h'as been foundthat compounds" similar to :those well known tor the-'rubber compounding art; which have been.

" usedin the past for: tire-curing water bags will be suitableformak-ingthe diaphragm of thepres ent apparatus:

The air pistonv is required :to lift no more than the weight 1 of".the'short: cylinder,- the. mold and ""thedocking mechanism; The pressurerequired.

touaccoinplish this-is so low thatthe cylinder itself maybeverylightpSincethe airpiston needlift -only a light loadiit is faster inactionthan ahydrauliclcylinder thereby effecting a saving in "'timexduring theoperationof closing the press.

When the'shortrhydraulic cylinder is used in com bination withu-thelow-pressure air cylinder, the two can :be :built :into a comparativelylight press frame and:atpthesameetf'me exert pressure equivalent: tothat01 K813-old lfiazly'heavy'hydraulic. press of'more massive: proportionsand sloW operatingcharacteristics; Thisproduces savings in- 1 both 1'the cost: 'ot' construction and installation as: well .asin time; andc0st"of operation,

It will" bex-appreciated that not all moldedarticles willrrequiresasplit' female mold member of-thecharacter'desoribed' Flat articles orconcavoconvex articleshaving 'a shallow :body por tion-donotrequire-opening'of the moldin order toremovethe article :from the'mold.The upper ders andthe; bag 'mustibe-sufi'icient to-produce bonding, oflayers :of: fabriczandrresin: The preshorizontal-hydrauliczcylinder (it!is needed only" whenarsplit mold: is required."

Thermolding. apparatus disclosed herein is a greatlyvimprovedctoolofconsiderable importance:

" tmztheeart:.oi:;rapid:molding:of:plastic. articless It:

is adaptable with equal facility to the molding of flat thin pieces anddeep thin-walled items, such as binocular carrying cases, case covers,golf bags, etc., and for blanking, forming and trimming sheet material.I

The chief advantages derived from the use of this apparatus are:comparative cheapness of the press itself, use-of high pressure fluid ina light press which is easily operated, economy in the use of highpressure fluid, the advantage of not having to remove the mold from thepress in order to put in blanks and to remove the molded product, theadvantage of a faster molding cycle made possible by the fast openingand closing of this press, and a further saving in labor for it ispossible to utilize female labor of the light weight class to operatethis apparatus. In addition, the molding apparatus of this invention isquickly and easily adaptable to the changes of temperature and pressurenecessary when molding different materials, or when the mold shape ischanged, or when the material thickness is increased. The press of thisinvention is faster and more efficient than conventional pressessuitable for molding large articles.

While I have described my invention in considerable detail asillustrated by a prefererd embodiment, it will be understood thatmodifications therein may be made without departing from the true spiritand scope of the invention as it is defined by the appended claims.

I claim:

1. Apparatus for molding deeply contoured,

hollow concave-convex articles such as helmet liners, binocular carryingcases and the like, said apparatus comprising a frame having a pair ofupstanding columns, a male mold member of metallic material dependingbetween said columns, said member being cored for heating and havingcommunicating means for supplying'heating fluid thereto, a flexiblediaphragm of extensible material associated with and separate from saidmale member so as to define a fluidtight chamber therewith,communicating means connecting with said fluid-tight chamber forsupplying fluid under pressure thereto, communicating means connectingwith said fluid-tight chamber for exhausting fluid therefrom, means insaid exhaust means for restricting the return of fluid thereto, a deeplycontoured female mold membermounted for vertical movement toward andaway from said male mold member, said female mold member beingvertically divided and one of the divided parts being hinged so as toswing open, the divided parts of said female mold member being c'oredfor heating and having communicating means for supplying heating fluidthereto, a low-pressure air cylinder and piston assembly mounted betweensaid uprights so as to raise and lower said female mold, opposed lockingseats on said columns, a rotary latch casting adapted to support saidair piston at an approximate molding position, said latch casting beingcarried by said air piston and being adapted for manual rotation aboutsaid air piston into and out of engagement with said locking seats, ashort-stroke high pressure hydraulic cylinder mounted on said airpiston, said hydraulic cylinder being adapted to move said female moldmember from said approximate molding position to final moldingrelationship with said male mold member, a second short-stroke highpressure hydraulic cylinder mounted to act in a direction to maintainthe divided female mold members in molding relationship, and apneumatically operated kicker cylinder arranged for engagement withfemale mold assembly while it is out of moldmember mounted in fixedrelationship to said frame, said member being cored for heating by theintroduction of heating fluid thereto, a flexible diaphragm ofextensible material associated with said male mold member and beingsecuredaround the base thereof so as to define a fluid-tight chambertherewith, communicatin means for connecting with said fluid-tightchamber introducing fluid under pressure thereto, means for exhaustingfluid from said chambenmeans for restricting the return flow ofexhausted fluid to said chamber, a deeply contoured female mold membermounted for vertical movement toward and away from said male mold memberand being adapted to mate with the male mold member, said female moldmember being divided substantially in half and the divided parts thereofbeing hinged so as to swing open to permit introduction of the blankarticle before molding, said female mold members also being cored forheating by the introduction of a heating fluid thereto, a pneumaticcylinder and piston assembly for raising and lowering said female moldmember, a short-stroke high pressure hydraulic cylinder mounted on saidair piston and in turn having a piston floatingly supporting said femalemold member, op-

posed locking seats on the upright frame, a lock- 7 ing member carriedon said air piston adapted for manual rotation into and out ofengagement with said locking seats, said locking member serving tosupport the hydraulic cylinder and female mold in molding relationshipwith the male mold member, and a second short-stroke high pressurehydraulic cylinder mounted to exert high molding pressure in a directionto maintain the divided portions of said female mold member in moldingrelationship.

3. Apparatus for molding deeply contoured concavo-convex articles, saidapparatus comprising a frame, a female mold member, a male mold membercomprising a convex metallic member and a flexible diaphragm ofextensible material overlying said convex metallic member-so as to forma fluid-tight chamber therewith, means for heating both mold members,means for supplying fluid under pressure to said fluid-tight chamberunder static pressure so as to favor superheating of said fluidin saidchamber, means for exhausting fluid from said chamber, means forrestricting return flow of fluid to said chambenone of said mold membersbeing mounted for verticalmovement toward and away from the other ofsaid mold members, pneumatically operated means for raising and loweringsaid movable mold member into and out of approximate moldingrelationship with the other of said mold members, manually operatedlocking means for positioning said movable mold member in saidapproximate molding relationship, short-stroke hydraulic means carriedby said pneumatically operated means, said hydraulic means in turnengaging and supporting said movable mold member-and being arranged soas to move said mold member into final molding relationship with theother of said mold members.

4. Apparatus for molding concavo-convex arthereof, a convexmoldmemberg-bothof said mold members being cored ior'heating' and havingcommunicatin means for supplying'heating fluid r thereto, said convexmoldmembercomprising an elongatedelement or metallic material and aflexible diaphragm of extensible material-"overlying saidelementandformingafluid tight cham- =-cham-ber and -means for'preventing influx'offluid to-saidexhaustedbhamber.

7.'- Molding apparatus comprising a "concave heated moldmember, a matingconvexmoldmember,--said*convex mold member being-a metallic memberhaving an overlying diaphragm of extensible"material defining-afluid-tight chamber with sai'd meta'llic member, one of said moldmembers being "movable toward and away "-from"theother ber therewith,one 'of' said "mold-member's being motor saidmoldmembers,pneumatic'means 'for movmounted for-movement "toward and away from theother of said' mold'members, pneumatically operated means for relativelym-ovingsaid movable mold members into'and out-of approximate saidpneumatic means in approximate-molding short-stroke hydraulicallyoperated means for movement of said movable'moldmember'intohydraulically operated means-acting in conjunction with said firsthydraulic means for-maintaining said split portions of'said'concavemember'in final molding relationship, means for heatingboth mold membersymeans fordntro'ducing- 2 fluid under pressure to saidchamber; means "i or exhausting fluid from said chamber,-means forrestricting the'return influx of fluid theretoy'and fast-action kicker'means'for opening the split portions of said concave'mold membertofacilitate removal of thefinished articletherefrom.

5. Apparatus for molding'concavo-convexarticles, said apparatuscomprising a' frame; a concave mold membersplit and hinged'for ready ingsaid movable mold member,-lock-ing-means --ior"*-po'sitioning saidmov'ablemold member in "approximate molding relationship, hydraulicmeans'mounted ior 'travel withsaid' movable mold molding relation,lockingmeans'for pos'itioning dwme fibe nd'" Ct byd fl o line with theimo'vement ---oi isaid "movable "mold member se-as to i move it intofinal molding relationship *with the othenof saidmold membersymeans forintroducing" an evaporable -liquid "to said fluidfinal moldingrelationship, auxiliary 'short-strokezago tight chamber under conditionsof static pressure,-='-means"-for exhausting said liquid from saidchamber and'for restricting'the return of fluid to *s'a-idchamberfor-creating a vacuum =under=said flexible diaphragm and thereby pullingsaid dia- 5 phragm away from 'the molded article.

SL -In" -a" "moIding appara-tus' 'hav-ing within a "press frame a moldadapted to'be taken apart for introduction of molding materialand'ionremoval of -the -molded article: a compound'pressureexerting meanscomprising a pneumaticallyoperatedfifast actionelevating means forelevating one of=said mold members into approximate molding relation-tothe tlier ofsaid' nild members, 'means for positio'ning sai'delevating means in introduction of molding material and removal ofapproximate molding p t fs fls ;hi

the finished article, a convexmold"member-having a flexible diaphragm ofextensible material forming a fluid-tight "chamber therewith;pneumatically operated means for moving one of'said pressure hydrauliccylinders A acting in conjunc- -tionwithsaid positione'd el'evatingmeansto close said mold in' fln-al molding relationship and a high-pressurehydraulic =pressure exerting bag m m e b t d t, at l -"540' withinsaid'mold acting in direct expansive oppoing relation with the other ofsaid mold members, locking means independent of saidi'pne'umatic meansfor positioning saidipneumatic'imeans'in said approximate. moldingrelationship, h'y'drausition'to'said cylinder-s said'bag and-saidhydraulie*pressure-exerting means beings'upplied with highpressu-refluid or the same pressure an'd'irom "thesam'e source, saidhydraulic cylinders exerting lically operated means in conjunction withsaid 6 0CIOSGSaidmold always q a to pneumatic means for .movingsaidmovable. mold member into flnalmolding relationship, hydraulicallyoperated means independent. of. said. pneuthe "forceeXerted-by -saidba'g'tending to open saidmold.

-9. In-'a 'm'oldin'g apparatus the combination matic means for.maintaining-the .split portions,- o'withlatmolldl'adapted 'tobetakenapartforintro of said concavemold memberzin flnalamoldingrelationship, means for supplying heat to both mold members, means forsupplying. fluidaunder pressure to said chamber, and meansiorrpermitting efiiuxof said fluid from said fluld-tight cham- 1. drauhcpressuredexertmg means for exerting high ber but restricting influx offluid thereto.

6. Apparatus for moldingconcavo-convex articles, said apparatuscomprising a heated .con-

cave mold member, a convex, mold member, said *molding pressureandahigh-'pressure "hydraulic pressurewxertingbag within said mold actingin directexpansive opposition'to said hydraulicpressure-exerting-means,'-said bag and said hydraulic cam/ex mold membercomprising ajheated metal *pressure 'exert-ing means-being supplied withhigh he member and an overlying "flexible diaphragm of extensiblematerial defining-a fluid-tight chamber therewith, pneumatic means formoving'one of said mold members toward and away from the -pressurefluid'oflthe same pressure and from the "same source, said hydraulic"pressure-exerting means'exerting a force'to close said mold alwaysequal to -or greater than'the forceexerted by said other of said moldmembers, I0'Cking means for hag tending to bpen said m positioning "saidmovableomol'dimember in-" approximate 'molding relation -to' the othersaid 10. "'In' "a molding apparatus the combination *with'a moldadapte'dto betakenapai't for introductionof the *moldingmaterial and forremoval of *the' molded article of a compound pressureexerting means"comprising fast-action L'pneu- "matica'lly operatedm'eansfor openingand closing said mold, short-travel, high pressure hydraulicpressure-exerting means mounted for travel with a portion of said moldfor exerting high molding pressure against said mold, a high-pressurehydraulic pressure-exertin bag within said mold acting in directopposition to said hydraulicpressure-exerting means, said hydraulicpressureexerting means exerting a force to close said mold always equalto or greater than the force exerted by said bag tending to open saidmold, means for supplying from the same source an evaporable fluid underthe same pressure to said hydraulic pressure-exerting means and saidbag, and means for maintaining a slower rate of flow to said bag than tosaid cylinders.

11. In a molding apparatus the combination with a mold adapted to betaken apart for introduction of the molding material and for removal ofthe molded article of a compound pressureexerting means comprisingfast-action pneumatically operated means for opening and closing saidmold, short-travel, high pressure hydraulic pressure-exerting meansmounted for travel with a portion of said mold for exerting high moldingpressure against said mold, a high-pressure hy draulic pressure-exertingbag within said mold acting in direct opposition to said hydraulicpressure-exerting means, said hydraulic pressureexerting means exertinga force to close said mold always equal to or greater than the forceexerted by said bag tending to open said mold, means for supplying fromthe same source an evaporable fluid under the same pressure to saidhydraulic pressure-exerting means and said bag, means for, maintaining aslower rate of flow to said bag than to said cylinders, means forexhausting said fluid from said hydraulic means and said bag, and meansfor preventing the influx of fluid and air to said bag after exhaust.

12. In a molding apparatus, the combination of a female mold member, amale mold member comprising a metal inner member and a diaphragm ofextensible material overlying the said inner member and forming afluid-tight cham-, ber therewith, one of said mold members being movableinto and out of molding relationship with the other, means forintroducing pressure fluid into said chamber, fluid pressuremeansincluding a piston urging the two mold members together directlyagainst the expansive force exerted by said diaphragm, said chamber andsaid fluid-pressure means being supplied with fluid under pressure froma common source and the effective area of said piston exceeding theefiec-- tive projected area of said diaphragm so that the force tendingto close the mold by reason of pressure in said fluid pressure meansalways exceeds the force tending to open the mold by reason of pressurein said chamber. I

13. Molding apparatus comprising within a press frame, a mold comprisinga plurality of members one of which is a deep concave member split atgenerally right angles to the main parting line ofthe mold for insertionof molding material and for removal of the finished article, the otherof said mold members being a deep convex stationary member adapted tocooperatively receive said movable, opening mold member, a compoundpressure-exerting means, said compound pressure-exerting meanscomprising a fast action elevating device for moving said movable moldmember into approximate molding relation with respect to the stationarymember, a plurality of coacting hydraulic pressureexerting means adaptedby operating generally 12 at right angles to maintain the opening memberof said mold in molding relation and a hydraulic pressure-exerting bagwithin said mold acting in direct expansive opposition to said coactinghydraulic pressure-exerting means, and means for breaking open saidopening member of said mold to facilitate removal of the finishedarticle.

14. Molding apparatus comprising within a press frame, a mold comprisinga plurality of members one of which is arranged to be movable and to beopened at generally right angles to the main parting line of the moldfor insertion of molding material and for removal of a finished article,the other of said mold members being stationary to cooperatively receivesaid movable opening mold member, a compound pressureexerting means,said compound pressure-exerting means comprising a fast actionpneumatically operated elevating device for elevating said opening moldmember into approximate molding position with relation to the other saidmember, a plurality of hydraulic pressure-exerting means adapted tocoact substantially at right angles to close the opening member of saidmold and to maintain the members of said mold in molding relation, and ahydraulic pressure-exerting bag Within said mold.

15. Molding apparatus comprising a concave mold member, a mating convexmold member, rapid-acting means for moving one of said mold memberstoward and from the other, means for positively locking the mold membersin approxi" mate molding relationship, means coacting with said lockingmeans for moving said mold mem bers into final molding relationshipunder high pressure, said convex mold member comprising a convex dome ofrigid material and a concavoconvex diaphragm of extensible materialoverlying the rigid dome and forming a fillid tight chamber therewith,means for supplying an evaporable liquid under pressure to said chamber,means for positively confining said liquid in said chamber, means forheating said liquid to a temperature above its normal boiling point,,andmeans for collapsing said diaphragm against said dome by reducing thepressure within said cham her through the evaporation of said liquid andthe cooling of the evaporated liquid below its boiling point, the lastsaid means comprisin exhaust means for rapidly exhausting the chamber tosubstantially atmospheric pressure including means responsive to theflow of fluid through said exhaust means to prevent the intake of fluidthrough the exhaust means.

FRANK J. MACDONALD.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,370,185 Capps Mar. 1, 19211,906,328 Maynard May 2, 1933 1,943,996 Williams et al. Jan. 16, 19342,020.669 Williams Nov. 12, 1935 2,272,887 Allen Feb. 10, 1942 2,313,623Bungay Mar. 9, 1943 2,363,107 Young Nov. 21, 1944 2,363,431 MoorhouseNov. 21, 1944

